This study will examine the effects of an 8 week aerobic exercise training program (65% VO2 max) in men and women with non-insulin dependent diabetes mellitus on 1) insulin sensitivity measured immediately before and 24 hours after a bout of exercise; 2) selected qualitative and quantitative changes in lipid and lipoprotein metabolism; 3) hemostasis as measured by indices of fibrinogen and fibrinolysis; 4) quality of life.